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2013-11-21target-i386: yield to another VCPU on PAUSEPaolo Bonzini
After commit b1bbfe7 (aio / timers: On timer modification, qemu_notify or aio_notify, 2013-08-21) FreeBSD guests report a huge slowdown. The problem shows up as soon as FreeBSD turns out its periodic (~1 ms) tick, but the timers are only the trigger for a pre-existing problem. Before the offending patch, setting a timer did a timer_settime system call. After, setting the timer exits the event loop (which uses poll) and reenters it with a new deadline. This does not cause any slowdown; the difference is between one system call (timer_settime and a signal delivery (SIGALRM) before the patch, and two system calls afterwards (write to a pipe or eventfd + calling poll again when re-entering the event loop). Unfortunately, the exit/enter causes the main loop to grab the iothread lock, which in turns kicks the VCPU thread out of execution. This causes TCG to execute the next VCPU in its round-robin scheduling of VCPUS. When the second VCPU is mostly unused, FreeBSD runs a "pause" instruction in its idle loop which only burns cycles without any progress. As soon as the timer tick expires, the first VCPU runs the interrupt handler but very soon it sets it again---and QEMU then goes back doing nothing in the second VCPU. The fix is to make the pause instruction do "cpu_loop_exit". Cc: Richard Henderson <rth@twiddle.net> Reported-by: Luigi Rizzo <rizzo@iet.unipi.it> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Richard Henderson <rth@twiddle.net> Message-id: 1384948442-24217-1-git-send-email-pbonzini@redhat.com Signed-off-by: Anthony Liguori <aliguori@amazon.com>
2013-02-27target-i386: Use mulu2 and muls2Richard Henderson
These correspond very closely to the insns that we're emulating. Signed-off-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2013-02-19target-i386: Implement tzcnt and fix lzcntRichard Henderson
We weren't computing flags for lzcnt at all. At the same time, adjust the implementation of bsf/bsr to avoid the local branch, using movcond instead. Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-02-19target-i386: Use clz/ctz for bsf/bsr helpersRichard Henderson
And mark the helpers as NO_RWG_SE. Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-02-18target-i386: Implement PDEP, PEXTRichard Henderson
Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-02-18target-i386: Implement MULXRichard Henderson
Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-02-18target-i386: Use CC_SRC2 for ADC and SBBRichard Henderson
Add another slot in ENV and store two of the three inputs. This lets us do less work when carry-out is not needed, and avoids the unpredictable CC_OP after translating these insns. Signed-off-by: Richard Henderson <rth@twiddle.net>
2013-02-18target-i386: Make helper_cc_compute_{all,c} constRichard Henderson
Pass the data in explicitly, rather than indirectly via env. This avoids all sorts of unnecessary register spillage. Signed-off-by: Richard Henderson <rth@twiddle.net>
2012-12-19exec: move include files to include/exec/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-10-28target-i386: rename helper flagsAurelien Jarno
Rename helper flags to the new ones. This is purely a mechanical change, it's possible to use better flags by looking at the helpers. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2012-10-01x86: Implement SMEP and SMAPH. Peter Anvin
This patch implements Supervisor Mode Execution Prevention (SMEP) and Supervisor Mode Access Prevention (SMAP) for x86. The purpose of the patch, obviously, is to help kernel developers debug the support for those features. A fair bit of the code relates to the handling of CPUID features. The CPUID code probably would get greatly simplified if all the feature bit words were unified into a single vector object, but in the interest of producing a minimal patch for SMEP/SMAP, and because I had very limited time for this project, I followed the existing style. [ v2: don't change the definition of the qemu64 CPU shorthand, since that breaks loading old snapshots. Per Anthony Liguori this can be fixed once the CPU feature set is snapshot. Change the coding style slightly to conform to checkpatch.pl. ] Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-08-14x86: switch to AREG0 free modeBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Remove temporary wrappers and switch to AREG0 free mode. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 in segmentation helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Rename remains of op_helper.c to seg_helper.c. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for misc helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for SMM helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for SVM helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for integer helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for condition code helpersBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-08-14x86: avoid AREG0 for FPU helpersBlue Swirl
Make FPU helpers take a parameter for CPUState instead of relying on global env. Introduce temporary wrappers for FPU load and store ops. Remove wrappers for non-AREG0 code. Don't call unconverted helpers directly. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-06-28x86: avoid AREG0 for exceptionsBlue Swirl
Add an explicit CPUX86State parameter instead of relying on AREG0. Merge raise_exception_env() to raise_exception(), likewise with raise_exception_err_env() and raise_exception_err(). Introduce cpu_svm_check_intercept_param() and cpu_vmexit() as wrappers. Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-01-11target-i386: fix SSE rounding and flush to zeroAurelien Jarno
SSE rounding and flush to zero control has never been implemented. However given that softfloat-native was using a single state for FPU and SSE and given that glibc is setting both FPU and SSE state in fesetround(), this was working correctly up to the switch to softfloat. Fix that by adding an update_sse_status() function similar to update_fpu_status(), and callin git on write to mxcsr. Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2009-10-23target-i386: implement lzcnt emulationAndre Przywara
lzcnt is a AMD Phenom/Barcelona added instruction returning the number of leading zero bits in a word. As this is similar to the "bsr" instruction, reuse the existing code. There need to be some more changes, though, as lzcnt always returns a valid value (in opposite to bsr, which has a special case when the operand is 0). lzcnt is guarded by the ABM CPUID bit (Fn8000_0001:ECX_5). Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2009-10-04target-i386: add RDTSCP supportAndre Przywara
RDTSCP reads the time stamp counter and atomically also the content of a 32-bit MSR, which can be freely set by the OS. This allows CPU local data to be queried by userspace. Linux uses this to allow a fast implementation of the getcpu() syscall, which uses the vsyscall page to avoid a context switch. AMD CPUs since K8RevF and Intel CPUs since Nehalem support this instruction. RDTSCP is guarded by the RDTSCP CPUID bit (Fn8000_0001:EDX[27]). Signed-off-by: Andre Przywara <andre.przywara@amd.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
2009-05-22x86: Add support for resume flagJan Kiszka
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
2008-11-17TCG variable type checking.pbrook
Signed-off-by: Paul Brook <paul@codesourcery.com> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5729 c046a42c-6fe2-441c-8c8c-71466251a162
2008-09-25SYSENTER/SYSEXIT IA-32e implementation (Alexander Graf).balrog
On Intel CPUs, sysenter and sysexit are valid in 64-bit mode. This patch makes both 64-bit aware and enables them for Intel CPUs. Add cpu save/load for 64-bit wide sysenter variables. Signed-off-by: Alexander Graf <agraf@suse.de> git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5318 c046a42c-6fe2-441c-8c8c-71466251a162
2008-08-30Fix some warnings that would be generated by gcc -Wredundant-declsblueswir1
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5115 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-18HLT, MWAIT and MONITOR insn fixes (initial patch by Alexander Graf)bellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4746 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-04reworked SVM interrupt handling logic - fixed vmrun EIP saved value - ↵bellard
reworked cr8 handling - added CPUState.hflags2 git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4662 c046a42c-6fe2-441c-8c8c-71466251a162
2008-06-0432 bit SVM fixes - INVLPG and INVLPGA updatesbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4660 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-28SVM reworkbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4605 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-22proper helper definition registering (all targets must do that)bellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4530 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-22cmpxchg8b fix - added cmpxchg16bbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4522 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-21convert eflags manipulation insns to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4515 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-21converted LSL/LAR/VERW/VERR to TCG - force 16 bit memory access for LSL/LARbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4513 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-21converted INTO/CMPXCHG8B to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4510 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-17BSR/BSF TCG conversionbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4477 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-17converted condition code supprot to TCG - converted shift ops to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4470 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-15converted more helpers to TCG - fixed some SVM issuesbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4459 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-12converted more helpers to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4447 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-12converted x87 FPU ops to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4444 c046a42c-6fe2-441c-8c8c-71466251a162
2008-05-12converted SSE/MMX ops to TCGbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4441 c046a42c-6fe2-441c-8c8c-71466251a162
2008-02-01use the TCG code generatorbellard
git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3944 c046a42c-6fe2-441c-8c8c-71466251a162